JPH07243419A - Seal rubber for pipe connection and method for connecting pipe - Google Patents

Abstract

PURPOSE:To provide a connection method, which can connect a pipe with extremely simple work when connecting a square pipe or a round pipe with a large bore, and seal rubber suitable for it. CONSTITUTION:This seal rubber is equipped with a tubular side wall 2, which engages with the insides of the tips of two pipes 7 and 7, a narrow circular projection 3, which projects outward from one end of the side wall 2, and a fin 4 with a fixed width, which is fixed in circular shape continuously along the inside periphery of the side wall 2. The seal rubber 1 for pipe connection, where the fin 4 is fixed at the base 5 to the inner face of the sidewall 2 and the tip 6 is fixed to project obliquely inward to the inner face of the sidewall 2, in the direction where it goes away from the circular projection 3, is engaged each so that each circular projection 3 may abut on each end face of the pipes 7, 7. Both ends of a connection joint 8 consisting of a pipe, which has an outside sectional form roughly the same shape as the inside sectional form of the pipe 7 and a little smaller than it, are inserted to push open the fins 4 inward of the seal rubber 1 each, thus the pipe 7 and the connection joint 8 are connected with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting pipes such as a round pipe and a square pipe, and a seal rubber used for the connection.

[0002]

2. Description of the Related Art To connect two pipes having a relatively large diameter to each other in an airtight manner, a flange is welded to each end face of the two pipes to be connected, and a packing is sandwiched between the flanges to attach a bolt. The method of fastening is used most commonly. In addition, a method of connecting pipes to each other with an expansion joint made of rubber or the like is also used.

[0003]

In the conventional pipe connecting method using the above-mentioned flange, since the flange projects to the outside of the pipe, the width of the flange when the pipe is to be laid along the wall surface of the building. In addition, it is necessary to float the pipe from the wall surface for piping only in the space required for fastening the flange, and it is not possible to pipe along the wall surface exactly, so that the volume of the space required for piping is large. Become. For example, in order to cleanly install a pipe such as a rainwater drainage pipe on an elevated road in a neat appearance, it is desirable to connect a pipe having a quadrangular cross section as close as possible to the wall surface.

There is also a problem in that it takes a lot of work to fasten the flange with a bolt. In addition, the conventional method of connecting pipes using flanges does not provide flexibility, so
There is little tolerance for vibration of the pipe after piping and deviation of the pipe, and there is a risk of damage to the pipe due to these causes. The expansion joint is used to prevent this, but it is difficult to reliably and airtightly connect the expansion joint to the end of a pipe having a relatively large diameter, and a large fastener is required. In particular, it is difficult to hermetically connect a rectangular pipe to the expansion joint.

Therefore, according to the present invention, when connecting a square pipe or a round pipe having a relatively large diameter to each other, there is no such thing as a conventional flange that projects to the outside of the pipe, and the pipes can be connected by a very simple operation. An object of the present invention is to provide a connecting method and a sealing rubber suitable for the connecting method.

A further object of the present invention is to provide a method of connecting pipes which can be connected securely and easily even with a pipe having a rectangular cross section.

Another object of the present invention is to provide a pipe connecting method in which the connecting portion of the invention has some flexibility and is somewhat tolerant of vibration and displacement of the pipe.

[0008]

[Means for Solving the Problems] In order to achieve the above object,
As a result of earnest studies, the present inventor has used a connecting joint made of a pipe having an outer cross-section slightly smaller than the inner cross-sections of two pipes to be connected, and the inside of the pipe to be connected at both ends of the connecting joint. By loosely fitting and sealing the gap between the pipe and the inner connecting joint airtight with a seal rubber, the pipe can be connected without overhanging a flange or the like on the outside of the pipe, and the inner surface of the outer pipe serves as the seal rubber. The fins are airtight and seal the rubber and the inner connection joint by providing a plurality of stages of fins that are slanted inward with a constant width and are annularly continuous in the inner circumference. The present invention has been completed by discovering that the pipe and the connection joint can be airtightly connected to each other.

That is, according to the present invention, in a seal rubber for fitting a pipe having substantially the same shape as the inner shape of the pipe and a slightly smaller outer diameter inside the end portion of the pipe to seal the gap between the two pipes, the inner surface of the outer pipe is A cylindrical side wall portion having an outer shape that is in close contact with the side wall portion, an annular protruding portion having a narrow width protruding outward from one end of the side wall portion, and a fixed width continuously fixed in an annular shape along the inner periphery of the side wall portion. Having a fin having
The fin is fixed to the inner surface of the side wall portion so that the tip is fixed to the inner surface of the side wall portion obliquely inward in the direction away from the annular protrusion. And

According to another aspect of the present invention, the above-mentioned sealing rubbers having side wall portions that fit snugly inside the tips of the two pipes to be connected are fitted so that the annular projections abut the end faces of the pipes. , So that the both ends of a connecting joint made of a pipe having substantially the same shape as the inner cross-sectional shape of the pipe to be connected and having an outer cross-sectional shape slightly smaller than the inner cross-section push the fins inside the seal rubbers. The gist is a method of connecting a pipe by pushing the pipe and connecting the pipe and the connection joint.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the seal rubber of the present invention will be described in detail below with reference to the drawings. 1 is a plan view of an example of the seal rubber of the present invention, FIG. 2 is a front view thereof, FIG. 3 is a side view thereof, and FIG.
Is a sectional view taken along the line AA, and FIG. 5 is a sectional view taken along the line BB. The seal rubber 1 is fixed to a square pipe-shaped side wall portion 2 and one end thereof, and has an annular protruding portion 3 protruding slightly outward from the side wall portion 2, and the outer surface of the side wall portion 2 is in close contact with the inner surface of the pipe to be connected. And have a size. An annular fin 4 is fixed to the inner surface of the side wall portion 2 continuously along the inner circumference of the side wall portion 2 so as to project obliquely inward from the inner surface of the side wall portion 2 along the inner periphery thereof. The number of fins 4 may be one, but it is preferable that three to ten fins are arranged in parallel in a plurality of stages. Side wall 2 of fin 4
The direction that projects obliquely from the inner surface projects obliquely in the direction away from the annular projection 3. If the fins 4 are formed so that the base portion 5 fixed to the inner surface of the side wall portion 2 is thick and the fins 4 are made thin toward the tip 6, the flexibility of the tip becomes large and the adhesion to the inner connection joint becomes good, and This is preferable because the rigidity of the base is large and the restoring force of the deformed fin 4 is large.

The angle of the fin 4 with respect to the inner surface of the side wall portion 2 is not particularly limited, but the angle θ between the upper surface of the fin 4 and the inner surface of the side wall portion 2 is preferably 30 to 60 °, more preferably 40 to 50 °. The width d of the fin 4 is not particularly limited, but is 10 to 10 mm with respect to the pipe-shaped side wall 2 having a thickness of 200 mm square, for example.
Fins 4 with a width of 20 mm are used.

The material of the seal rubber 1 is not particularly limited,
Natural rubber or synthetic rubber having appropriate elasticity and durability is appropriately used, and it is desirable to integrally mold the whole.

FIG. 6 is a sectional view showing a case where square pipes are joined using the seal rubber 1 shown in FIGS. Pipe 7
Rubber with an outer shape that fits snugly on the inner surface of
Is fitted to the tip of the pipe 7 up to the annular projection 3 thereof, and then one end of a rectangular pipe-shaped connection joint 8 having substantially the same shape as the inner cross section of the pipe 7 but a slightly smaller outer cross section inside the seal rubber 1. When is pushed in, the fins 4 on the inner surface of the seal rubber 1 are expanded as shown in FIG. 6, and the tips of the fins 4 are bent toward the side wall portion 2 and come into close contact with the outer surface of the connection joint 8. By similarly pushing the other end of the connection joint 8 into the inside of the seal rubber 1 inserted into the inner surface of another pipe 7, the connection between the two pipes 7, 7 is completed. The gap D between the inner cross section of the pipe 7 and the outer cross section of the connection joint 8 is larger than the thickness of the side wall portion 2 of the seal rubber 1 as shown in FIG. A gap that can be pushed in is preferred.

As shown in FIG. 6, the connecting joint 8 is preferably provided with a narrow annular projection 9 on the outer periphery of its central portion.
Thereby, when both ends of the connection joint 8 are pushed into the seal rubber 1 fitted to the ends of the pipes 7, they can be pushed uniformly without being biased toward one of the pipes 7.

As shown in FIG. 6, instead of pushing both ends of the connection joint 8 into the inside of the seal rubber 1 fitted in the tip of the pipe 7, the connection joint 8 having a half length is welded to the tip of one pipe 7. Alternatively, the connection joint 8 and the tip of the other pipe 7 may be preliminarily joined by adhesion or the like and airtightly connected via the seal rubber 1 in the same manner as described above. Alternatively, it is possible to reduce the outer diameter of the tip portion of one pipe 7 to the thickness of the connection joint 8 and to connect the tip portion of the other pipe 7 and the tip end of the other pipe 7 airtightly using the seal rubber 1. is there.

The material of the connection joint 8 is preferably a metal such as steel having high rigidity and strength, but in some cases such as when there is a demand for corrosion resistance to a fluid flowing inside, it is made of a synthetic resin having appropriate strength and rigidity. May be

FIG. 7 is a plan view showing another embodiment of the seal rubber 1 of the present invention, which is a seal rubber having a circular cross section used for connecting round pipes. All are the same as the seal rubber 1 shown in FIGS. 1 to 5 except that the outer and inner cross sections are circular. Its side view is the same as FIG. 2, and its vertical sectional view is the same as FIG. The connecting joint 8 used when connecting the round pipes using the seal rubber 1 is a round pipe-shaped connecting joint 8 having a circular cross section, and the sectional view of the connecting portion of the pipe 7 is the same as that in FIG.

[0019]

According to the method of connecting the pipes 7 using the seal rubber 1 of the present invention, the seal rubbers 1 are fitted inside the tips of the two pipes 7 to be connected, and the tubular connection joints are inside the seal rubbers 1. The pipe 7 and the connection joint 8 are airtightly connected by simply pushing both ends of the pipe 8, and the connection between the two pipes 7 is completed. When the connection joint 8 is pushed into the seal rubber 1, the fins 4 on the inner surface of the seal rubber 1 are expanded and the tips of the fins 4 are bent outward, so that the fins 4 of the seal rubber 1 and the connection joint 8 are airtightly adhered to each other. Due to the elasticity of the curved fin 4 to restore,
The side wall portion 2 of the seal rubber 1 is pushed outward and expanded, and the outer surface of the side wall portion 2 strongly adheres to the inner surface of the pipe 7 to maintain airtightness.

Since the fins 4 of the seal rubber 1 are arranged obliquely in the direction in which the connecting joint 8 is pushed in, when the connecting joint 8 is pushed in, it can be pushed in relatively easily, but once the connecting joint 8 is pushed in. When pulling out, a considerably large force is required due to the resistance of the fins 4 facing in the direction opposite to the pulling direction. However, the connection joint 8 can be pulled out from the pipe 7 as needed for repair, and when a large tensile stress is applied between the pipes 7 and 7 in use, the connection joint 8 slides in the seal rubber 1 to cause stress. Can be relaxed and can also serve as an expansion joint.

Due to the elasticity of the seal rubber 1 inserted between the pipe 7 and the connecting joint 8, the connecting portion has some allowance for movement, and damage due to vibration or deviation of the pipe 7 is reduced.

The pipe connecting method of the present invention can be applied to any of drain pipes, liquid feed pipes such as water feed pipes, air feed pipes such as intake and exhaust ducts, and can be used for protection pipes such as electric wires buried in the ground. It can also be used for connection, and can be used for connection of various pipes.

The two pipes to be connected may have different diameters, or may have different shapes such as a square pipe and a round pipe. In that case, the shape of the pipes at both ends of the connection joint 8 may be changed according to the shape of the pipe to be connected, and a pipe having two pipes of different diameters or different shapes may be used.

[0024]

According to the seal rubber for pipe connection and the pipe connecting method of the present invention, the connecting work of the pipe 7 can be carried out very easily. Unlike the conventional pipe connecting method using a flange or the like, the flange does not project to the outside of the pipe 7, and the pipe 7 can be connected to the outside of the pipe 7 without projecting at all. It can be placed in close contact with the floor or the like, and the space required for piping can be saved. In particular, in the case of a pipe using a square pipe, the pipe can be placed almost in close contact with a wall surface and the like, and even an exposed pipe such as a drainage pipe of an elevated road that is exposed to the eyes does not spoil the appearance.

[Brief description of drawings]

FIG. 1 is a plan view of an example of a seal rubber for pipe connection according to the present invention.

FIG. 2 is a front view of an example of a pipe connecting seal rubber of the present invention.

FIG. 3 is a side view of an example of a seal rubber for pipe connection according to the present invention.

FIG. 4 AA of an example of a seal rubber for pipe connection of the present invention
FIG.

FIG. 5: BB of an example of a seal rubber for pipe connection of the present invention
FIG.

FIG. 6 is a cross-sectional view showing a method of connecting pipes using the seal rubber for pipe connection of the present invention.

FIG. 7 is a plan view showing another embodiment of the seal rubber for pipe connection of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seal rubber 2 Side wall part 3 Annular protrusion part 4 Fin 5 Base part 6 Tip 7 Pipe 8 Connection joint 9 Annular protrusion

Claims (4)

[Claims] 1. A seal rubber for fitting a pipe having substantially the same shape as the inner shape of the pipe and having a slightly smaller outer diameter inside the end portion of the pipe to seal the gap between the two pipes, and substantially adheres to the inner surface of the outer pipe. A cylindrical side wall having an outer shape, an annular protrusion having a narrow width protruding outward from one end of the side wall, and a fin having a constant width fixed in an annular shape continuously along the inner circumference of the side wall. The fin has a base portion fixed to the inner surface of the side wall portion, and the fin is fixed so as to project obliquely inward with respect to the inner surface of the side wall portion in a direction away from the annular protrusion. Seal rubber for connection. 2. The seal rubber for pipe connection according to claim 1, wherein a plurality of the fins are arranged in parallel in a plurality of steps on the inner surface of the side wall portion. 3. The seal rubber for pipe connection according to claim 1, wherein the both pipes are square pipes, and the side wall portion of the seal rubber has a tubular shape with a square cross section. 4. The seal rubber according to claim 1, wherein the two rubber pipes to be connected each have a side wall portion which fits snugly inside the front end portions of the two pipes, so that the annular protrusions abut the end faces of the pipes. Then, both ends of a connecting joint made of a pipe having substantially the same shape as the inner cross-sectional shape of the pipe to be connected and having an outer cross-sectional shape slightly smaller than the inner cross-section are expanded so that the fins are spread inside the seal rubber. A method of connecting a pipe by pressing the pipe to connect the pipe to be connected and a connection joint.